Tight winding device for timepieces



July 30, 1946. J. A. BoNlNcHl TIGHT WINDING DEVICE FOR TIMEPIECES Filed Aug. 25, 1942 1501@ @Zap Patented `luly 30, 1946 TIGHT WINDING DEVICE FOR TIMEPIECES Joseph Antoine Boninchi, Geneva, Switzerland, assignor to J. Boninchi & Ses Fils, Geneva, Switzerland, a firm of Switzerland Application August 25, 1942, Serial No. 456,053 In Switzerland September 30, 1941 4 Claims.

This invention relates to a tight winding device for time pieces which comprises a crown having a packing adapted to form a tight joint about the pendant neck of the watch-case. The invention primarily consists in that this packing presents a main body provided with an external flange, said main body being lodged with play in an annular recess of the crown while said liange is compressed between a shoulder of the crown and a clamping piece borne by the crown.

In order that the invention may be completely understood, attention is directed to the accompanying drawing in which Figure 1 is an axial sectional View of a preferred embodiment of the invention and Figures 2, 3 and 4 show modification of details.

In the form shown in Figure 1, I designates the case body, 2 the pendant neck and 3 the winding crown in which there is lodged a packing 4 adapted for use as a tight joint about the pendant neck 2. This packing is formed of a cylindrical main body IlEL and a flange 4b projecting externally from the periphery and at the lower portion of the main body. The main body 4a is lodged with play in an annular recess 5 of the crown while the ange 4b is compressed between a shoulder E of this crown and a clamping ring 1 set in the lower portion thereof.

In this way the compression necessary to maintain the packing merely acts on the portion of the flange which is clamped between shoulder 6 and ring 1 and thus the main body 4a is entirely free from compression. This is a considerable advantage, for when the compression is distributed on the whole packing it causes in the long run a flattening of this packing which reduces the central bore and a hardening of the compressible material thereof. As a result a too heavy friction occurs when winding-up the crown and after the crown has been removed from the pendant neck, for instance when repairing of the watch, it would be difcult to set it again into place. The small play reserved radially in the recess 5 of the crown permits the body la of the packing to be easily adjusted on the pendant neck notwithstanding the errors of calibration and without radial compression of the packing.

The embodiment shown in Figure 2 only diiiers from the form above described in that the shoulder 6 slightly projects inwardly from the outer wall of the recess 5.

In both those crowns the flange is made integral with the body of the packing. In the form shown in Figure 3 the flange is constituted of an annular projection of the packing body and a metallic washer 4d Xed on this projection. In the modification shown in Figure 4, the iiange only consists in a metallic washer 4e partly engaged in a peripheral groove of the packing body.

What I claim is:

l. A tight winding device for time pieces, the combination with a case body having a pendant neck Xed thereto, of a crown having an annular recess, a compressible packing tted about said neck and including a cylindrical main body spaced radially from the side wall of said recess and a lower flange projecting outwardly from the periphery of said main body, said main body having sealing contact with said pendant neck, a shoulder on the outer wall of said` recess and a clamping piece borne-by said crown, said llange of the packing being compressed between and having sealing Contact with said shoulder and said clamping piece.

2. A tight winding device as claimed in claim 1, wherein the flange is made integral with the cylindrical main body of the packing.

3. A tight winding device as claimed in claim i, wherein the flange comprises an annular projection of the main body and a metallic washer fixed on said projection.

4. A tight winding device as claimed in claim 1, wherein the flange only consists in a metallic Washer partly engaged in a peripherical groove of the main body.

JOSEPH ANTOINE BONINCHI. 

